this code is converted by intellij idea, I don't understand why it tonvert a f(a,b) in java to f(a)(b) in kotlin, auto currying? https://paste.ubuntu.com/p/NNbRwmR4mG/

I have an object:

class User {
      var id: String? = null
      var name: String? = null
    }

and list of pairs:

val fieldsToChange = listOf<Pair<String, String>>(Pair("name", "foo"), Pair("id", "bar"))

I would like to iterate trough list of pairs and set appropriate values for given properties using reflection. How I can achieve this using kotlin reflection?

I would love to see classes diagram of my project, to analyse architecture and dependencies between packages. Is there any tool I could use? Built-in Idea Ultimate diagram builder doesn’t seem to work with Kotlin

What’s the best approach to call a method after all

Jobs

stored in a

List<Job>

are completed?

hey Kotlineers, I've started a Kotlin prettier plugin https://github.com/Angry-Potato/prettier-plugin-kotlin, it's pretty simple and barebones so far, I'd love some more eyes on it if anyone else out there likes Prettier and wants to help bring it to Kotlin!

Is the such library as https://gatling.io/ in Kotlin?

Oh dear, Set.filter() returns a List rather than a Set.

EventCallback<Float> { if (it > 0) println("ouch!") else println("1") } I don't understand the syntax, put a type before a lambda, is ?

Is it not a design flaw to have

Any

extend

Unit

? This would be nice for overriding functions…

I don't understand why java/kotlin have List and Array, 'cause C only have Array, Python only have List, Haskell have List, why java/kotlin have both? what's the meaning???

a = [0..100] and b = {"a":1, "b":2} are so simple and plain to use

Hi guys, Is there a way of parsing Kolin code? A library or something like that in order to obtain the function names, parameters, parameters types and outputs?

how do i use

mapto

plus

takeif

in chain, so that only those which satisfy operation are mapped to an arraylist?

Guys, is it possible to create a function for both array and collection? They don't even have iterable in common 😞

The line

return@tryLambdas

should throw an error here right? It does if i make it return

String

directly instead of generics. not sure what is going on here, could this be cause of type erasure?

inline fun T tryLambdas(lamb : () -> T) : T{
    return lamb.invoke()
}

fun main() {
    tryLambdas<String>{
        return@tryLambdas // this should throw an error, but it doesnt. on decompiling it replaces it with Unit.INSTANCE
    }
}

Does anyone know a better way of doing this type of thing? using

!!

always makes me feel icky

val x: Int? = getAnIntegerOrMaybeANullFromAPlaceO
if (x != null) {
    functionThatTakesNonNullableIntegerArgument(x) // won't compile because it thinks x is nullable
    functionThatTakesNonNullableIntegerArgument(x!!) // will compile because added !!
} else {
    // handle the null case
}

(Just in case a future Java version changes what ZonedDateTime will parse, or we switch to a different calendar or something...)

Is there a way to tell the Kotlin compiler to treat certain Java methods with a

void

return as

Nothing

instead of

Unit

?

Came across some Platform type issues related to annotations this week, and while I've used platform types before, never really thought deeply as to why they exist. Seems like everything that's returned from Java could just be treated as nullable. Looking at the docs:

Any reference in Java may be null, which makes Kotlin's requirements of strict null-safety impractical for objects coming from Java. Types of Java declarations are treated specially in Kotlin and called platform types. Null-checks are relaxed for such types, so that safety guarantees for them are the same as in Java

It seems as though it was a conscious decision to make the platform conform to Java. There are tradeoffs with all those choices, but curious as to why the reasoning was made to create the platform type instead of treating everything as nullable?

It’s just an iterable of iterables of

T

which gets flattened into a list of

T

. Here’s an example:

[[1, 2, 3], [4], [5, 6]] -> flatten -> [1, 2, 3, 4, 5, 6]

I just found something a bit puzzling in the language (thread)

Hi all. How to access the R of kproperty1 <T, R>? For exemple: class Foo (val name: String) val test: String = Foo::name (getting error: "Required String, found KProperty1<Foo, String>)

Is class delegation (composition) considered a type of Mixin? Kinda confused on semantics.

my most desired features by likelihood they'll ever be added: * possible: default parameter types * unlikely: list literals.... * impossible: unbounded-range w/ operator

Perhaps someone (more qualified than me) should add a kotlin example to lazy initialization here: https://en.wikipedia.org/wiki/Lazy_initialization

Hey guys! I very like kotlin cause it’s very agile for the most situation f.e. I wanna have postfix version for ternary operator(i understand position of lang-developers about if-else). So, that’s my first solution:

fun <T> Boolean.ternary(first: T, second: T) =
        if (this) first
        else second

Any pro-programmer will tell u that in cases like this

(stringA != null).ternary(stringA!!, stringB!!)

we will have npe(parameters of function calculates before call). Lets make our function inline and add reified type:

inline fun <reified T> Boolean.ternary(first: T, second: T) =
        if (this) first
        else second

Nice! Now for non-primitives classes we will not have any trouble. I guess u’ve already understand what I mean. For primitives it doesnt work, cause even for inline function kotlin calculates primitive expressions and then call function. For me it’s looks like a bug. Does anybody know will it be fixed for next versions?

fun counter():()->Int{
 var c=0
 fun g():Int{
  c++
  return c
 }
 return g
}

why “Function invocation g() expected”?

is it possible to do partial application with KFunction1 (to reduce it to KFunction0)

I keep hearing about something soon to be added to Kotlin that allows us to modify the compiler. What is that?